International audience ; Arbuscular mycorrhizal fungi (AMF) play a crucial role in ecosystem functioning by improving plant nutrition and resistance to environmental stress. In La Gran Sabana (LGS), a high plateau belonging to the Venezuelan Guayana Shield, with vegetation mainly composed by savannas intermixed with forests, shrublands, meadows and palm swamps, the AMF are determinant for plant survival due to the acidic, sandy and oligotrophic nature of its soils. In this region a high diversity of species of Gigasporaceae has been found and four species discovered there (Scutellospora spinosissima, S. crenulata, S. striata, S. tepuiensis), and some undescribed morphotypes, are considered endemic. In this work, some ecological and historical factors possibly involved with the restricted distribution of these species are evaluated. The elevated plant endemism and the particular edaphic conditions present in shrublands appear like the main drivers of the important diversification processes within Gigasporaceae detected in LGS. The monophyletic origin of some of these endemic Gigasporaceae suggests that their endemism could be the result of a process of in situ diversification combined with limitations for dispersal and/or establishment in other regions. These findings and the presence of a basal lineage for the family allows proposing LGS as an evolutionary hotspot for Gigasporaceae.